Compacted lawn-what to do!

masie · Hazel Tree Joined: 04 Apr 2007 Posts: 3 Location: limerick

hi there,
I am very new to the the world of gardening and have a few questions about managing our lawn. We moved house last summer and the back garden was filled and compacted with lots of topsoil. The grass was waterlogged for much of the winter and is now discoloured. There are trees planted in various places throughout the lawn. Is it okay to spray the soil (as per previous post) with trees present? Will a hand-held rotavator be good enough? Should we drain the garden? I'd really appreciate any advice... Thanks Confused

verge

Hello masie. Yes, it was a wet winter, which may have led to the swamping of your lawns roots with water, impeading oxygen and leading to yellowing. But it may not be just rainfall onto the lawn which can cause waterlogging. Check for burst water pipes, patios or hard surfaces can also offload their water onto lawns, if either is the case, you must stem the flow of water. Also close by houses built recently may have a hard surface such as a driveway or yard sending extra water your way.

It might be that the soil is just compacted and standing water is compacting it further. Compaction leads to poor drainage and this can encourage moss. Small areas can be aerated by inserting a garden fork into the lawn at regular intervals. However this can become tiresome if you have a large area and a simple manual push aerator will greatly speed up the process. A well aerated lawn will allow water, air and nutrients to get down to the roots of the grass where they are needed, thus ending your yellowing.
The lawn may just need aeration, see this post
http://www.gardenplansireland.com/forum/viewtopic.php?t=398

Of course the soil may be ok, but you may have a compacted layer of subsoil beneath it, which is preventing drainage of water from the topsoil. If that is the case, you will have to dig trenches deeper than 3ft to break the layer and install drainage piping. Here is a helpful post within Irish gardeners on installing soil drainage, if you have to go to that extreme http://www.gardenplansireland.com/forum/about783.html

GPI

Masie, try pushing a wooden matchstick into your lawns surface.
You should also be able to easily press a matchstick full into the soil with your thumb.
On an uncompacted lawn you will be able to do this without any pain or breaking of the matchstick, provided you don't hit a stone, of course. Very Happy

Heres an image to give you an idea of the soils layers.....

Both or either of the two layers (subsoil & topsoil) can become compacted, smeared and panned whilst siteworks are undertaken.
Its also worth bearing in mind that if it is the topsoil which is compacted, then granular lawn fertiliser will have little effect on the yellowed turf.
This is because the fertiliser is unable to travel to all the roots in a compacted soil.

masie · Hazel Tree Joined: 04 Apr 2007 Posts: 3 Location: limerick

Thanks a million for the prompt replies and advice. We have about half acre of dodgy lawn- fun times ahead!!